Carbonated beverages consist of carbonated water and a syrup flavoring combined together in a desired ratio. In post-mix beverage dispensing systems the syrup and carbonated water are mixed at the time of dispense, whereas in pre-mix systems, a previously blended carbonated drink is dispensed from a container holding a volume thereof. Since the pre-mix beverage is produced at a bottling facility, it has the advantage of high quality in terms of accurate carbonation level, ratioing and high water purity. However, since carbonated beverages are typically five parts carbonated water to one part syrup, pre-mix suffers from the disadvantage of requiring the transportation of large volumes of water. Thus, post-mix dispensing, where "local" water is utilized and carbonated on sight, has a cost advantage over time, especially in high volume permanent dispensing locations. Nevertheless, pre-mix systems are very desirable in low volume and temporary special events locations, where water quality is low, and as pre-mix dispensing equipment is less expensive and generally more portable than post-mix equipment.
However, a problem with pre-mix dispensing concerns the uptake of CO.sub.2 into the beverage in excess of the desired level during the time the beverage remains in its container. This uptake occurs due to the fact that pressurized CO.sub.2 is used as the motive force to move the beverage from its container to a cooling dispenser and ultimately out a pre-mix dispense regulating valve and into the cup being filled. As a result, if the beverage is in physical contact with the pressurized CO.sub.2 for a long enough period of time, over carbonation will result. Consequently, when dispensed, such an overly carbonated beverage has a much increased tendency to foam. Excessive foaming wastes beverage and causes delays in filling a cup to its proper level.
Pre-mix beverage dispensing systems, as indicated above, use valves to provide for the on/off regulation of the dispensing of the pre-mixed beverage. As is understood in the art, a carbonated beverage is relatively delicate in that pressure changes and turbulation thereof can cause the carbon dioxide component to come out of solution, thereby resulting in a flatter less carbonated drink than is desired. Thus, where for example, a fresh container of pre-mix is being used wherein CO.sub.2 uptake has not occurred to any significant extent, it is desirable to have a pre-mix dispensing valve that serves to minimize any such carbonation loss attributable to its dispensing function. Unfortunately, the uptake of CO.sub.2 discussed above is usually in excess of what the dispensing process will remove as the beverage flows through the valve and into the cup. In any event, the overlap in time during which both processes may negate each other would be fleeting and otherwise completely uncontrollable. Thus, a valve that minimizes carbonation loss attributable to its function would be desirable.
It is also understood that pre-mix valves require the holding or placement below the nozzle thereof of a cup followed by manipulation of an upward extending control lever located on top of the valve. Typically, this process requires two hands wherein one hand holds the cup and properly positions it beneath the nozzle, while the other operates the lever. Or alternately, at least requires the placement of the cup on a rest below the nozzle, followed by the manipulation of the valve control lever. It is desirable to have a valve that permits one handed operation wherein the cup can be held beneath the nozzle and the valve actuated by the same hand simultaneously, especially where a cup rest is not present or convenient or the operator has only one free hand. Prior art pre-mix valves have means for easier operation but have definite short comings. A solenoid operated valve is known but it entails the cost of that electromechanical adaptation. Downward extending levers that are positioned beneath the valve so as to permit operation in the above described one handed manner are known. However, such valves are configured to essentially require substitution off the existing control lever with a lever that extends downward below the valve nozzle in the opposite direction of the traditional lever. The substituted lever interacts with the internal valve actuating shaft mechanism at the same pivot point. Thus, it confers no, or even less, mechanical advantage with respect to the force required to open the valve than what would be normally present with the standard lever. As is known in the art, pre-mix valves are designed so that the pressure of the beverage, as pushed by the driving gas, bears against the valving mechanism to bias it in the closed position. The force required to overcome this pressure is sufficient that if a typical paper or styrofoam cup is pushed against such a downward extending prior art lever, such cups can be easily crushed or otherwise deformed. As a result, beverage may miss the cup or the cup can be rendered unsuitable for retail sale.
Accordingly, it would be desirable to have a pre-mix dispensing system that is lower in cost than existing systems and performs to consistently present a carbonated beverage with the desired level of carbonation. It would also be desirable to have a pre-mix valve that can be operated in a one handed manner without causing cup damage and to do so without adding significant cost and complexity to the valve.